Ms. Masters, 44, a veteran of the swaps industry, will sit on a global markets committee that will meet next week to discuss the overseas application of the CFTC’s rules. The committee also includes executives from Citigroup Inc. and Goldman Sachs Group Inc. Banks have largely opposed the CFTC’s efforts to extend its swaps rules overseas.

While in her 20s, Ms. Masters was among the team of J.P. Morgan bankers who helped breathe life into the market for credit-default swaps to shift risk off the bank’s books.

The CFTC has pushed aggressively to make the swaps market more transparent and safer in the wake of the financial crisis, when banks’ swaps trades soured. The CFTC’s efforts have prompted blowback from the industry, particularly controversial November guidance clarifying that overseas banks must adhere to CFTC rules if they book a swaps deal abroad but use U.S.-located personnel to arrange, execute or negotiate the transactions. Three industry groups subsequently filed suit against the agency over its guidance.

Ms. Masters joins the CFTC panel as her bank moves to sell its multi-billion dollar physical commodities operations, dismantling a business Ms. Masters had spent several years developing. The business had created legal headaches for the bank stemming in part from a federal electricity regulator’s investigation that the bank engaged in manipulative electricity-bidding behavior. The bank agreed to pay $410 million to settle the accusations in July.

A spokesman for J.P. Morgan declined to comment on Ms. Masters’ appointment.